2013 has heralded (the beginning of) the end of three major pop musicians' careers: Kesha, Demi Lovato, and Justin Bieber.


Kesha: self-explanatory.
Demi Lovato's new single, which many of her fans claimed would 'slay,' is already out of the Top 10 on iTunes and #34 on Kworb.net.
Bieber, who used to be a great single seller, has a new single with Will.I.Am that has failed to go Top 5 on iTunes.
WHICH ARTIST'S CAREER IS THE MOST OVER?